An electrochemical device includes a cathode, a separator and an anode. The cathode includes a cathode current collector, a first cathode active material layer including a first cathode active material, a second cathode active material layer including a second cathode active material, and an insulating layer. The first cathode active material layer is disposed between the cathode current collector and the second cathode active material layer, and the first cathode active material layer is disposed on a first region of a surface of the cathode current collector facing an anode active material layer of the anode, and the thickness of the first cathode active material layer is greater than Dv50 of the first cathode active material. The insulating layer is disposed on a second region of the surface of the cathode current collector not facing the anode active material layer of the anode.